Multi-layer infill system for synthetic grass

ABSTRACT

A cost-effective synthetic turf system with a plurality of layers of infill material. According to various embodiments, a synthetic turf system includes synthetic grass and a plurality of layers of infill material. In one embodiment, the upper layer of infill particles generally “sit” on top of a lower layer of smaller particles. Because the smaller particles will tend to become more densely packed, the larger particles will tend to remain on top of the smaller particles. In certain embodiments, the upper layer is treated with a light colorant, such as green, yellow, white, etc. Depending on field and environmental conditions, the coloring may reduce surface temperatures by up to 30% compared to conventional infills.

CLAIM OF PRIORITY

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 62/106,801, filed Jan. 23, 2015, entitled,“MULTI-LAYER INFILL SYSTEM FOR SYNTHETIC GRASS,” incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to synthetic grass, and moreparticularly to a synthetic grass system with vertical grass bladesforming a matrix that encapsulates an infill having at least a lowerlayer of smaller resilient particles and a substantially segregatedupper layer of larger resilient particles.

BACKGROUND

Synthetic turf systems are popular replacements for natural grass.Previous synthetic turf systems used infill materials spread between thesynthetic “grass” fibers in an attempt to provide a safer surface. Theprevious systems used a high percentage of sand infill. However, thesesystems become hard and less shock absorbent over time, and the sand isabrasive to both the athlete and the turf system. This leads toincreased player injuries and a shortened life span of the turf system.

Angular sands used in these types of infill will also migrate to thebottom of the turf system and clog the perforations in the turf system,thereby reducing the percolation rate of the turf system over time.

Other conventional systems use resilient infill, such as “crumbrubber”—rubber from used tires ground into small particles. However, sunon the black rubber infill can cause very hot surface temperatures. Thecrumb rubber infill also has the potential for off gassing of odors thatis sometimes unpleasant to athletes and spectators. Also, the blackparticles are aesthetically offensive.

Therefore, there is a long-felt but unresolved need for a syntheticgrass that provides an improved safe playing surface while alsopreventing hot surface temperatures and avoiding undesirable odors.

BRIEF SUMMARY OF THE DISCLOSURE

Briefly described, and according to one embodiment, aspects of thepresent disclosure generally relate to synthetic grass. According tosome aspects of the present disclosure, a synthetic turf system includessynthetic grass and a plurality of layers of infill material. In oneembodiment, an upper layer of infill particles generally “sit” on top ofa lower layer of smaller particles. Because the smaller particles willtend to become more densely packed, the larger particles will tend toremain on top of the smaller particles. In certain embodiments, theupper layer is treated with a light colorant (e.g., dyed), such asgreen, yellow, white, etc. Depending on field and environmentalconditions, the coloring may reduce surface temperatures by up to 30%compared to conventional infills.

It is an object of the present disclosure to provide an infill that willretain its properties throughout use without compaction of the infilland with a reduced requirement for periodic brushing of the surface.

It is a further object of the present disclosure to provide amulti-layer (e.g., two-layer or more) infill system that willsignificantly reduce surface temperature throughout use, becost-effective to produce, and will comprise infill layers that remainsubstantially segregated when in use to achieve certain performanceproperties.

It is a further object of the present disclosure to provide amulti-layer infill system that will eliminate unwanted odors, reduce thechance of bacterial growth on the field and eliminate any “fly out” ofthe resilient particles. It is a further object of the presentdisclosure to provide an aesthetically pleasing colored (e.g., green)surface at a significantly reduced cost.

To overcome the issues and challenges described in the background aboveand to accomplish the objects recited herein, the present disclosureattempts to utilize at least two layers of infill particles—an upperlayer comprising larger particles (which, in certain embodiments, willbe treated with a colorant to exhibit certain heat-reduction properties)and a lower layer of traditional particles (not color treated). Thus,the present technology can obtain the benefits of treating the upperparticles with a colorant to keep the turf cool during high heatseasons, but also avoid significant additional cost by limiting theamount of colored (and generally more expensive) particles needed forinfill.

In one embodiment, a synthetic grass system, comprising: a backinglayer; a plurality of generally upstanding synthetic grass bladesaffixed to the backing layer; and at least two layers of infillparticles generally interspersed amongst the plurality of generallyupstanding synthetic grass blades, the at least two layers of infillparticles comprising: an upper layer of particles; and a lower layer ofparticles, wherein the lower layer of particles are generally smaller insize as compared to the upper layer of particles.

In one embodiment, a process of providing a synthetic grass systemcomprising the steps of: providing a backing layer; providing aplurality of generally upstanding synthetic grass blades affixed to thebacking layer; distributing a first lower layer of particles utilizing auniform pattern of spreading with a mechanical spreader; distributing asecond upper layer of particles utilizing a uniform pattern of spreadingwith a mechanical spreader; wherein the upper layer of particles aregenerally larger in size as compared to the lower layer of particles.

In one embodiment, a synthetic grass system comprising: a backing layer;a plurality of generally upstanding synthetic grass blades affixed tothe backing layer; and at least two layers of infill particles generallyinterspersed amongst the plurality of generally upstanding syntheticgrass blades and resting on the backing layer, the at least two layersof infill particles comprising: an upper layer of particles, wherein theupper layer of particles comprises resilient particles treated with acolorant and substantially sized in a range of about 8-16 mesh, and alower layer of particles, wherein the lower layer of particles comprisesparticles not treated with a colorant and substantially sized in a rangeof about 16-20 mesh.

According to one aspect of the present disclosure, the synthetic grasssystem, wherein the particles of the upper layer are treated with alight colorant sufficient to exhibit heat-reduction properties. Further,the synthetic grass system, wherein the particles of the upper layer aredyed green. Further, the synthetic grass system, wherein the particlesof the lower layer are not treated with a colorant. Further, thesynthetic grass system, wherein the upper layer comprises a light color.Further, the synthetic grass system, wherein the lower layer comprisesresilient particles. Further, the synthetic grass system, wherein theresilient particles of the lower layer are selected from the groupconsisting of: crumb rubber, micronized rubber power, and elastomermaterial. Further, the synthetic grass system, wherein the upper layercomprises resilient particles. Further, the synthetic grass system,wherein the resilient particles of the upper layer are selected from thegroup consisting of: crumb rubber, micronized rubber power, andelastomer material. Further, the synthetic grass system, wherein thelower layer comprises sand. Further, the synthetic grass system, whereinthe difference in size between the particles of the upper layer andparticles of the lower layer is sufficient for the particles of theupper layer to substantially settle on top of the particles of the lowerlayer. Further, the synthetic grass system, wherein the lower layer ofparticles comprises particles substantially sized in the range of 10-20mesh. Further, the synthetic grass system, wherein a majority of theparticles comprising the lower layer of particles are sized in the rangeof about 16-20 mesh. Further, the synthetic grass system, wherein amajority of the particles comprising the upper layer of particles aresized in the range of about 8-16 mesh.

According to one aspect of the present disclosure, the process ofproviding a synthetic grass system, wherein the particles of the upperlayer are treated with a light colorant sufficient to exhibitheat-reduction properties. Further, the process of providing a syntheticgrass system, wherein the particles of the upper layer are dyed green.

These and other aspects, features, and benefits of the claimedinvention(s) will become apparent from the following detailed writtendescription of the preferred embodiments and aspects taken inconjunction with the following drawings, although variations andmodifications thereto may be effected without departing from the spiritand scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments and/oraspects of the disclosure and, together with the written description,serve to explain the principles of the disclosure. Wherever possible,the same reference numbers are used throughout the drawings to refer tothe same or like elements of an embodiment, and wherein:

FIG. 1 (consisting of FIGS. 1A and 1B) is a side cross-sectional view ofa synthetic turf system, according to aspects of the present disclosure.

FIG. 2 is a side cross-sectional view of an alternate embodiment of asynthetic turf system having additional layers of resilient particlesaccording to aspects of the present disclosure.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings and specific language will be used todescribe the same. It will, nevertheless, be understood that nolimitation of the scope of the disclosure is thereby intended; anyalterations and further modifications of the described or illustratedembodiments, and any further applications of the principles of thedisclosure as illustrated therein are contemplated as would normallyoccur to one skilled in the art to which the disclosure relates. Alllimitations of scope should be determined in accordance with and asexpressed in the claims.

Aspects of the present disclosure generally relate to synthetic grass.According to some aspects of the present disclosure, a synthetic turfsystem includes synthetic grass and a plurality of layers of infillmaterial. In one embodiment, an upper layer of infill particlesgenerally “sit” on top of a lower layer of smaller particles. Becausethe smaller particles will tend to become more densely packed, thelarger particles will tend to remain on top of the smaller particles. Incertain embodiments, the upper layer is treated with a light colorant(e.g., dyed), such as green, yellow, white, etc. Depending on field andenvironmental conditions, the coloring may reduce surface temperaturesby up to 30% compared to conventional infills.

Synthetic turf systems may be used for sports fields, track facilities,golf courses, landscaping, and other indoor or outdoor facilities.

Now referring to the drawings, FIGS. 1A and 1B show a synthetic turfsystem 101 according to aspects of the present disclosure. In oneembodiment, the synthetic turf system includes a pile fabric having abacking 1 and a multiplicity of generally upstanding grass-like pileelements 2. In various embodiments, the backing may comprise a wovenlayer or a combination of woven and non-woven layers. The height andother characteristics of the grass-like pile elements 2 may vary basedon intended use. In various embodiments, the height of the grass-likepile elements 2 ranges from 1.5 inches to 2.5 inches, while in otherembodiments the height may be outside that range. An infill overlyingthe backing is interspersed between the upstanding pile elements. Theinfill includes a plurality of layers of infill material (described ingreater detail below). In the embodiment shown in FIGS. 1A and 1B, theturf 101 includes two layers, a lower layer 3 and upper layer 4.

To maintain the two (or more) layers of particles, in one embodiment,the upper layer 4 includes larger particles that generally “sit” on topof the smaller particles of the lower layer 3. In particular, becausethe smaller particles will tend to become more densely packed, thelarger particles will tend to remain on top of the smaller particleseven during extended use of the synthetic turf. In various embodiments,the lower layer occupies about two-thirds of the total infill depth, theupper layer occupies about one-third of the total infill depth, and thetotal infill depth reaches to about three-quarters of the height of thegrass-like pile elements 2. In other embodiments, the depth of eachlayer of infill and the total infill depth may vary. FIG. 1B shows thatthere may be some intermingling of particles from the upper layer andlower layer; however the layers are substantially segregated.

According to the embodiment shown in FIGS. 1A and 1B, the infill isapplied in 2 layers. The lower layer 3 sits on the backing 1. In variousembodiments, the lower layer 3 includes resilient particles such as, butnot limited to, crumb rubber, micronized rubber powder, or otherelastomer material. In some embodiments, the lower layer 3 may becomprised of sand or other granular material. In one embodiment, theupper layer 4 sits on top of the lower layer 3 and also generallycomprises particles of rubber or another resilient material. In oneembodiment, the particles of the upper layer 4 comprise a colored rubberor color coated rubber (e.g., colored light green or another lightcolor, such as white, light yellow, or light brown).

In some embodiments, each layer has distinctly different mesh or sievesize. As would be understood by one having ordinary skill in the art,“mesh” refers to a standard test for particle sizing. Particles areplaced on a mesh screen with openings of a particular size. When themesh is shaken, particles larger than the mesh size are retained on themesh, while smaller particles generally pass through. For example, 10mesh means there are 10 squares across one linear inch of screen. Alarger mesh size therefore represents smaller particle sizes.

As shown in FIGS. 1A and 1B, the upper layer of infill 4 comprises crumbrubber or other resilient materials generally uniform in size. In oneembodiment, the size of the particles in the upper layer 4 is between8-16 mesh. In certain embodiments, the upper layer 4 is colored (e.g.,light green instead of black). Depending on field and environmentalconditions, the coloring may reduce surface temperatures by up to 30%compared to conventional infills. The colorant may also include ananti-microbial agent that will reduce any chance for bacterialinfection, help eliminate any related smell on the field. The largerparticles in the upper layer 4 stop migration of the black (lower layer)crumb rubber particles. Further, the colored upper layer 4 resilientinfill provides an aesthetically pleasing surface at a significantlyreduced cost compared to coloring all infill. Generally, color-treatedparticles are more expensive than untreated particles. In someembodiments the lower layer 3 is not color treated (e.g., the particlesare left their original color, such as black).

In some embodiments, the lower layer 3 and upper layer 4 should not bemixed together and should be applied separately in different courses orlayers in which the relative proportions and size of the two types ofparticles differ.

According to one embodiment, the multi-layer infill product describedherein comprises the following characteristics (when a two-layerapproach is used, as illustrated in FIGS. 1A and 1B):

Lower layer 3: between about 10-20 mesh, majority falling between about16-20 mesh. These particles may be reused infill with all rubber or amixture of sand and rubber, or some other combination as will occur toone of ordinary skill in the art. In one embodiment, the lower layer 3comprises 30-70% of total infill by weight. One specific nonlimitingexample of the composition of particles in a lower layer 3 is asfollows:

Percent Mesh Passing MM Microns No. 10 100 2.00 2000 No. 12 98 1.68 1680No. 14 98 1.41 1410 No. 16 51 1.19 1190 No. 18 40 1.00 1000 No. 20 260.841 841

In some embodiments, installation of the lower layer 3 should beperformed in stages (also called lifts) of approximately 0.5 lbs persquare foot of resilient particles utilizing a uniform pattern ofspreading by means of a mechanical spreader, each layer should begroomed with a sweeping machine, and sprayed with a solution of dilutedfabric softener to eliminate static electricity and allow the particlesto slide into place. Upon the final lift of the lower layer 3 particles,the surface should be groomed, sprayed with the fabric softenersolution, and blown with air prior to installation of the upper layer 4.

Upper layer 4: between about 8-16 mesh colored rubber or (resilientcolored particle) making up the remainder of weight of infill. Onespecific nonlimiting example of the composition of resilient particlesin upper layer 4 is as follows:

Percent Mesh Passing MM Microns No. 8 92 2.38 2380 No. 10 78 2.00 2000No. 12 52 1.68 1680 No. 14 40 1.41 1410 No. 16 22 1.19 1190

Installation of the upper layer 4 should be performed in lifts ofapproximately 0.5 lbs per square foot of resilient particles utilizing auniform pattern of spreading by means of a mechanical spreader, eachlayer should be groomed with a sweeping machine, and sprayed with asolution of fabric softener to eliminate static electricity and allowthe particles to slide into place.

After installation, the resultant turf field should be groomedperiodically. New fields should be groomed once a week for the first twomonths. In some embodiments, the brush of a grooming machine should notpenetrate the lower layer 3 more than 0.25 inches to avoid mixing ofinfill. The field should be groomed from sideline to sidelinealternating the direction of travel, i.e. towards the home side orvisiting side on successive grooming cycles. In some embodiments, anylon soft bristle drag system should be used, such as one manufacturedby Gandy.

FIG. 2 shows an alternative embodiment of a synthetic turf system 101,with more than two layers of particles according to one embodiment ofthe present disclosure. As shown, layers 5, 6, and 7 are intermediatelayers of particles that sit above the lower layer 3 and below the upperlayer 4. In various embodiments, the turf system 101 may have any numberof infill layers of varying sizes and properties.

The embodiments were chosen and described in order to explain theprinciples of the claimed inventions and their practical application soas to enable others skilled in the art to utilize the inventions andvarious embodiments and with various modifications as are suited to theparticular use contemplated. Alternative embodiments will becomeapparent to those skilled in the art to which the claimed inventionspertain without departing from their spirit and scope. Accordingly, thescope of the claimed inventions is defined by the appended claims ratherthan the foregoing description and the exemplary embodiments describedtherein.

What is claimed is:
 1. A synthetic grass system comprising: a backinglayer; a plurality of generally upstanding synthetic grass bladesaffixed to the backing layer; and at least two layers of infillparticles generally interspersed amongst the plurality of generallyupstanding synthetic grass blades, the at least two layers of infillparticles comprising: an upper layer of particles; and a lower layer ofparticles, wherein the lower layer of particles are generally smaller insize as compared to the upper layer of particles.
 2. The synthetic grasssystem of claim 1, wherein the particles of the upper layer are treatedwith a light colorant sufficient to exhibit heat-reduction properties.3. The synthetic grass system of claim 1, wherein the particles of theupper layer are dyed green.
 4. The synthetic grass system of claim 2,wherein the particles of the lower layer are not treated with acolorant.
 5. The synthetic grass system of claim 1, wherein theparticles of the upper layer comprise a color substantially lighter thanthe particles of the lower layer.
 6. The synthetic grass system of claim1, wherein the lower layer comprises resilient particles.
 7. Thesynthetic grass system of claim 6, wherein the resilient particles ofthe lower layer are selected from the group consisting of: crumb rubber,micronized rubber power, and elastomer material.
 8. The synthetic grasssystem of claim 1, wherein the upper layer comprises resilientparticles.
 9. The synthetic grass system of claim 8, wherein theresilient particles of the upper layer are selected from the groupconsisting of: crumb rubber, micronized rubber power, and elastomermaterial.
 10. The synthetic grass system of claim 1, wherein the lowerlayer comprises sand.
 11. The synthetic grass system of claim 1, whereinthe difference in size between the particles of the upper layer andparticles of the lower layer is sufficient for the particles of theupper layer to substantially settle on top of the particles of the lowerlayer.
 12. The synthetic grass system of claim 1, wherein the lowerlayer of particles comprises particles substantially sized in the rangeof 10-20 mesh.
 13. The synthetic grass system of claim 12, wherein amajority of the particles comprising the lower layer of particles aresized in the range of about 16-20 mesh.
 14. The synthetic grass systemof claim 12, wherein a majority of the particles comprising the upperlayer of particles are sized in the range of about 8-16 mesh.
 15. Aprocess of providing a synthetic grass system comprising the steps of:providing a backing layer; providing a plurality of generally upstandingsynthetic grass blades affixed to the backing layer; distributing afirst lower layer of particles utilizing a uniform pattern of spreadingwith a mechanical spreader; distributing a second upper layer ofparticles utilizing a uniform pattern of spreading with a mechanicalspreader; wherein the upper layer of particles are generally larger insize as compared to the lower layer of particles.
 16. The process ofproviding a synthetic grass system of claim 15, wherein the particles ofthe upper layer are treated with a light colorant sufficient to exhibitheat-reduction properties.
 17. The process of providing a syntheticgrass system of claim 16, wherein the particles of the upper layer aredyed green.
 18. A synthetic grass system comprising: a backing layer; aplurality of generally upstanding synthetic grass blades affixed to thebacking layer; and at least two layers of infill particles generallyinterspersed amongst the plurality of generally upstanding syntheticgrass blades and resting on the backing layer, the at least two layersof infill particles comprising: an upper layer of particles, wherein theupper layer of particles comprises resilient particles treated with acolorant and substantially sized in a range of about 8-16 mesh, and alower layer of particles, wherein the lower layer of particles comprisesparticles not treated with a colorant and substantially sized in a rangeof about 16-20 mesh.